In the past, there have been many different types of modular electronic systems having a chassis with a variety of modules that can be interconnected to the back plane of the chassis. However, the electrical components in the modules tend to generate large amounts of heat when they are in use. Therefore, to accommodate the heat generated by the electrical components these conventional electronic systems generally use fans or other air moving means to force air flow across the modules in order to dissipate the generated heat. However, the forced-air cooled modular electronic systems do not operate well in harsh environments for a number of reasons. First, in harsh environmental conditions, it is not always possible to have the fan operational and a fan failure may not become immediately apparent, which may cause other components to fail before the fan failure is noticed. Second, in harsh environmental conditions, which tend to also be dirty conditions, the air generally has dust and other airborne contaminants contained therein, such that perpetually forcing air around delicate electronic components may eventually cause undesired failures decreasing the “Mean Time Between Failures” (MTBF) of the modules.
To address some of the MTBF issues and provide more reliable operation, conduction-cooled enclosed chassis have been used in the past in some harsh environmental conditions. However, because conduction cooled enclosed chassis are enclosed, they are not modular and do not permit reconfiguration of the systems by the exchange of modules therein. Furthermore, such conduction cooled enclosed chassis must be entirely replaced even if a single component fails. As a result, such conduction cooled enclosed chassis give rise to maintenance and replacement issues in the field, which cause Mean Time To Repair (MTTR) to decrease.
Furthermore, in addition to protecting the electrical components against harsh environmental conditions, including dust, dirt and heat, it is also desirable to protect the electrical devices from shock and vibration. An acute shock, or prolonged vibration, may lead to failure of highly sensitive electronic devices thereby also decreasing the mean time between failures (MTBF).
Accordingly, there is a need in the art to provide a modular electronic system which can operate in harsh environments without the use of a forced air cooling system. There is also a need in the art for a modular electronic system which is resistant to environmental conditions, such as dirt, vibration and shock to approve desired MTBF and MTTR levels.